To ensure that the downloaded ROM is not corrupted, you can check its MD5 or SHA-1 hash. You can use tools like MD5 Checker or Hash Calculator to verify the ROM's integrity.

Click on the download link and save the ROM file to your computer. The file extension should be .nds or .bin .

Ensure that you're downloading the Spanish version of Dark Souls, also known as "Soul of Darkness" or "Darksiders" (not to be confused with the different game, Darksiders). Verify that the ROM is specifically labeled as "Spanish" or "Español."

If you have a DS console, you can transfer the ROM to your console using a flash card or a device like the R4. If you're using an emulator like DeSmuME, you can load the ROM file directly into the emulator.

This guide is for educational purposes only, and I encourage users to support the game developers by purchasing a physical copy of the game.